Undetected fabric damage, human error and the wind brought down the dome at B.C. Place Stadium a week ago, according to a preliminary engineering report released on Friday.
Bellingham-based Kris Hamilton of Geirger Engineering said he spotted previously undetected damage to the fabric roof panelthat gave way, while doing an onsite survey the day after the deflation.
He said the suspect section was well hidden and out of view. But he said it appears the actions ofstadium stafftriggered the accident.
That morning, the workers noticed the speaker ceiling columns were hanging low, and that the Teflon-coated fiberglass fabric roof was slightly inverted.
Hamilton said that while one staff person went to a computer to start an additional fan to raise the roof a bit, a second worker started eight other fans.
That led to an over-pressurization, which, coupled with the weakened panel and the prevailing winds,made ahuge tear in the panel.
At that point,stadium staff deflated the massive domed roof.
Hamilton is recommending that B.C. Place change its air-control system to prevent a recurrence.
Stadium general manager Howard Crosley said all of Hamilton's recommendations will be implemented immediately.
A new panel needed to patch the roof has arrived in Vancouver from the U.S. and is expected to be in place within a day or two.
Stadium officials says once that's done and other smaller tears are sealed, preparations will begin for reinflating the fabric dome.
The 24-year-old building is home to the B.C. Lions of the Canadian Football League, and is scheduled to be the venue for the opening and closing ceremonies for the 2010 Winter Olympics.